YES... I was keeping Pekins and Mallards together and had to separate them cause I was worried the pekins who are both drakes were going to kill the mallard females. This is also the reason you see mallards in the wild that mate for life. The mortality rate of female is SUPER high so when a male find a female he sticks with her. Normally birds like ducks, geese, chickens ect. that have babies that can forage for themselves are not monogamous because the male is not needed to care for the young like in song birds that give birth to helpless young. There are exception of course ie. mallards, swans and some other water foul... ok I am done rambling now.
